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The terms sensible heat and latent heat refer to energy transferred between a body and its surroundings, defined by the occurrence or non-occurrence of temperature change; they depend on the properties of the body. Sensible heat is sensed or felt in a process as a change in the body's temperature.
Temperature-dependency of the heats of vaporization for water, methanol, benzene, and acetone. In thermodynamics, the enthalpy of vaporization (symbol ∆H vap), also known as the (latent) heat of vaporization or heat of evaporation, is the amount of energy that must be added to a liquid substance to transform a quantity of that substance into a gas.
= latent heat of water vaporization, 2.45 [MJ kg −1], = specific heat of air at constant pressure, [MJ kg −1 °C −1], = ratio molecular weight of water vapor/dry air = 0.622. Both and are constants.
Substituting into the Clapeyron equation =, we can obtain the Clausius–Clapeyron equation [8]: 509 = for low temperatures and pressures, [8]: 509 where is the specific latent heat of the substance. Instead of the specific, corresponding molar values (i.e. L {\displaystyle L} in kJ/mol and R = 8.31 J/(mol⋅K)) may also be used.
The moist static energy is a thermodynamic variable that describes the state of an air parcel, and is similar to the equivalent potential temperature. [1] The moist static energy is a combination of a parcel's enthalpy due to an air parcel's internal energy and energy required to make room for it, its potential energy due to its height above the surface, and the latent energy due to water ...
The specific enthalpy of fusion (more commonly known as latent heat) of water is 333.55 kJ/kg at 0 °C: the same amount of energy is required to melt ice as to warm ice from −160 °C up to its melting point or to heat the same amount of water by about 80 °C. Of common substances, only that of ammonia is higher.
Enthalpies of melting and boiling for pure elements versus temperatures of transition, demonstrating Trouton's rule. In thermodynamics, Trouton's rule states that the (molar) entropy of vaporization is almost the same value, about 85–88 J/(K·mol), for various kinds of liquids at their boiling points. [1]
The Stefan number [1] (St or Ste) is defined as the ratio of sensible heat to latent heat.It is given by the formula =, where c p is the specific heat, . c p is the specific heat of solid phase in the freezing process while c p is the specific heat of liquid phase in the melting process.